Google Groups Used To Direct Trojan Malware

September 11, 2009 – 2:04 PM

Google’s free online newsgroup Google Groups hosts plenty of harmless user-generated content. But like any service that allows users to post information, it also turns out to be useful for “misuser-generated content.”

A Symantec security researcher has found that Trojan malware is using Google Groups to fetch commands for directing its attacks.

“A back door Trojan that we are calling Trojan.Grups has been using the Google Groups newsgroups to distribute commands,” said Symantec security researcher Gavin O Gorman in a blog post on Friday. “Trojan distribution via newsgroups is relatively common, but this is the first instance of newsgroup [command and control] usage that Symantec has detected.”

The Trojan is designed to request a page from escape2sun, a private newsgroup. The page lists instructions for the malware: an index number, a command line to execute, and, optionally, a file to download. The newsgroup also stores responses from the infected host. Commands and responses are encrypted, to conceal the information.

The Trojan itself doesn’t appear to be particularly sophisticated. The fact that the private newsgroup containing the commands is in simplified Chinese and the fact the stored commands include references to the .tw domain suggest the author(s) designed it to operate in Taiwan.